Pokemon Emerald Cheats :

This cheat for Pokemon Emerald [Game Boy Advance] has been posted at 21 Jun 2006 by A_mazing and is called "Hints - Catch Rayquaza With Using Master Ball". The Cheat have a rating -2 by 8 our users. If cheat is usable don't forgot thumbs up A_mazing and share this with your freinds. And most important we have 256 other cheats for Pokemon Emerald, look them as soon as possible!

Hints - Catch Rayquaza With Using Master Ball

ok this worked for me so it should work for you it worked for my friends when you are able to catch rayquaza as soon as u go into battle with him throw a ultra ball at him and as soon as it closes press and hold A you have to time it just right and i mean just right and you can catch him and that way can save the master ball for latios or latias